Knitting machine



Aug. 4, 1931. A. HOFMANN KNITTING MACHINE Fileddune 12, 1930 v INVENTOR BY WMM,"

I A TTORNEYS f Patented Aug. 4, 1931 UNITED STATES PATENT orries ALFRED HOFMANN, OF PALISADE, NEW JERSEY KNITTING Application filed .Tune 12,

- This invention relates to knitting machines, and "more especially is an improvement in the mechanism of straight knitting machines such as are used for manufacture of full fashioned knitted hosiery or other fabrics. For the purpose of illustrating the principles of the invention it is shown applied to a knitting machine of the Cotton type, or a machine employing a number or banks of united needles of the spring beard type, each bank adapted for the production of the leg or foot of a stockin or other knitted product; there being a num er of makesof such type of machine to which the invention is applicable.

The general object of the invention'is to improve the action of the needles, jacks, sinkers and other elements cooperating therewith, more especially in a way to improve'the product by eliminating the tendency to form undesired visible longitudinal stripes or streaks.

A particular ob'ect is to improve the operation of the sin ers, their actuating means and the jacks, so as to avoid the defect in operation and product already mentioned.

Other and further objects and advantages of the improvement will be pointed out in the hereinafter following description or will be apparent to those skilled in the subject. To

the attainment of such objects and advantages the present invention consists in the novel knitting machine and the novel features of combination, cooperation and construction herein illustrated or described.

In the accompanying drawings Fig. 1, partly in vertical transverse section and partly in side elevation, shows a, typical portion of a knitting machine of the class referred to, including the bearded. needles, sinkers, dividers and associated parts, sufiicient for the purposes of describing the present improvement,it being understood that standard machine may be referred to to supply other connections and parts not shown. Fig. 2 is a perspective view of a portion of Fig. 1. Figs. 3 and 4 are diagrams showing the relation of the thread, the needles, the sinkers and the dividers in two successive stages or positions wherein the present improvement is con- 50 cerned.

MACHINE 1930. Serial No. 460,843.

In Fig. 1 of the drawings a bar, .row or connected bank ofbearded needles 5 is indicated, it being understood that the entire row or bar of needles is united or held in a common clamping or supporting member or bar, as in the class of machine referred to. The means for laying the thread upon the needles is not shown, as it may be of any well 'known kind.

Cooperating with the needles is a row or bank of sinkers 7 of the sliding type, each of these having a notch 8 at its forward or needle end to engage and thrustthe thread into pre liminary loops and at the other end a butt 9 for cooperation with the actuating mechanism.

A bank of dividers 10 is shown each of which at its front or needle end has a notch 11 and at the other end a butt 12. The sinkers and dividers may be mounted above a supporting guide 14 above which is an overlying guide 15, the two guides being mounted at the top'of a member or carriage 16 which may have movement or adjustment in accordance with the practise in the art. A thrusting member 18 is shown adapted to effect the advancing of the dividers at the propertime, and associated with it is a member 19 for retracting the dividers and the sinkers. For example the thrusting and retracting members may move forwardly to advance the dividers and then descend sufiiciently to engage the butts of the sinkers and then retractto draw back the sinkers and dividers after the thread loops have been completed.

The sinkers are intended to be advanced prior to and independently of the dividers,

and in fact successively along the bank of sinkers. For this purpose a series of sinker advancing means is shown, consisting typically of a bank of jacks 21 each arranged to engage the'butt of a sinker and thrust it forward. Each jack is shown as having a nose 22 contacting directly with its sinker and at the other end'a tail 23 spring pressed at either of. its extreme positions. The entire bank of jacks may asusual be supported on a com- I monpivot or rod 24 and the successive ad- I. I

vanclng movements of the jacks and sinkers may be brought about by a member or cam 25 which is adapted to move longitudinally of the machine so as to cam the jacks forneedles, the sinkers 7 are thrust forwardl one at a time to produce a first set of loops of excessive depth. The sinkers are shown as operating in this manner between every alternate pair of needles but the arrangement might be varied, so long as the sinkers are spaced eriodically, leaving unlooped stretches of t read at intervals between needlesr After all of the first set of loops has ibeen formed the dividers come into play,

being thrust forward simultaneously as described so as to bring about the formation of the remaining loops 0 as shown in Fig, 4, at

the same time drawing back the loops b to their normal size, the sinkers 7 being held only yielding forward at this time to permit such drawing back of the first set of loops.

The resilient means tending to hold the jacks 21 and sinkers 7 in their advanced position, but permitting yieldin retraction as descrlbed, may comprise a ban of springs 27 pressing upon the jacks and thereby exerting their resilient pressure u on the sinkers. These are shown as long' s ank springs of the usual standard type, each of them having its free end formed with an ofi'set or hump at 28 grooved at its under or front side to maintain a pressing engagement upon the tail 23 of the corresponding jack and each spring having'at the other end a butt 29 by which this end of the spring may be anchored or firmly held in a supporting member, block or bar '31 extending longitudinally of the machine and rigidly holding or clamiing the-lower or rear ends of the entire ban of sprin Opposed to the supporting bar 31 is a c amping member or plate 32 interlocking with the bar and the two between them clamping the butt ends of the springs the parts being held in clamped position by a series of screws 33 placed at intervals along the length of the clamp plate and bar. It is understood that the supporting bar 31 may undergo an usual or desired movements during knitting operations.

In the knitting of stockings or other hosiery on machines of the class described it has been quite common or uent to find the roduct is streaked or stri with irregular ongitudinal effects due to some irregularity in the knitting action. The stripes themselves are not regularly placed and cause a disfigurement of the work and a substantially reduced market value. It has been the efiort for a long time to eliminate this defect and produce hosiery uniformly free from the streaks or stripes referred to. The reason for this defect noted has not been heretofore thoroughly understood and not overcome. On the supposition that irregularities in friction between the various elements may have caused the defect the attempt has been made to cure it by the application of oils or greases of different characters; which not only has not obviated the defect but has endangered the spoiling of the product by grease marks. On the supposition that, despite hi h accuracy in the manufacture of the sin ers, dividers and cooperating parts, they have not been sufiiciently exact and uniform to give uniformity of action along the length of the machine, effort has been made to increase the accuracy of manufacture of such parts, with consequent added expense but without over coming the defect.

With this invention the discovery has been made that the defective action, and the pro duction of the objectionable stripes, can be obviated by the introduction of means for modifying and rendering uniform the yielding resistance of the sinkers to the drawing back of the first set of loops while the dividers are producing the second set of loops. By reference to Fi s. 3 and 4 it will be understood that if, in the-yielding action of the sinkers, there is a difference of resistance, for example in one sinker as compared with an adjacent one, the product will not contain the uniform s as indicated in Fi 4, but will show a diiizarentiation in regar to the ultimate size ofithe res ective loops of the first set, due to the di erence in retracting movement as just described, which diflerence may be continued through row after row, thus producing a longitudinal efi'ect or stripe.

e present invention having been applied to the type of machine wherein the resisting springs act upon jacks which in turn act upon the sinkers, it is specifically the principle of the present improvement to modify the action 0 the s ring gremed jacks upon the sinkers b ren ering uniform the spring resistance 0 the entire banks of springs, jacks and sinkers, more es cially during the dividing action during w ichthe first set of loops-is drawn back to final size. There has therefore been devised and illustrated herein means cooperating with the bank of springs to render uniform the described yielding action, and at the same time the improved means preferably tends to render firmer the springpressure and resistance upon each individual jack and sinker; all of which is accomplished without sacrificing the advantages of the long shank s rings which have become standard in this 0 ass of machine.

The supplemental element or improvement hereof may be described as a longitudinal contact member or strip or abutment ar ranged to contact or-press upon the shanks of all the springs of the sinkers, during the strip in the same support or clamping means as the springs themselves. Thus .the strip is shown as having its lower or clamped end,36 mounted and confined between thev supporting bar 31 and the clamp plate 32, in a. positionsubstantially adjacent to the springs, preferably at their back or upper sides, that is the sides opposite to the sides which apply the resilient pressure to the jacks and sinkers.

. Preferably further the contact or pressure strip 35 does not lie contiguous to the springs over its entire width, but is shaped away from the springs beyond the clamp means, as clearl shown, and bent back or ofiset at the end 3 so as to afiord a contact line 38, at which line the strip contacts, equalizes and reenforces the bank ofsprings. Preferably, and as shown, the contact line 38 is not merely at the back sides of the springs, but is at a point substantially midway of the lengthof the springs, bywhich. is intended a point substantially removed from both the held ends and the free ends of the springs.

By'this specific mode of embodiment of the improvement there is no need of introducing any structural-change in the. existing machines, the only change being the introduction of the sprmg contacting or reenforcing strip 35 into the spring holding clamp. This improvement has been demonstrated and found to give highly satisfactory results in'the elimination of the undesired longitudinal stripes in hosiery. .The articular embodiment as shown also is suc as to permit, and not to interfere with, a slight play of each individual spring laterall of 1ts own length, by sliding longitudina ly upon the contact line of the strip 35, which is desirable. The disclosed arran ement also retains the advantage of the ull flexibility of each spring from its held end to its free end. The.

usual action of the springs therefore is not impaired since each can flex overits whole length and can slide laterally of its length as described.

Various modifications of arrangement and combination may be made within the scope of the invention. The contact strip 35, while preferably composed of brass or copper, and fairly thin so as to be stifiiy resilient, might be perfectly rigid. As preferred but not broadly essential details the contact strip 35 all times.

is shown mounted on the same supporting bar that holds the springs 27; and ism o rative contact with the springsiiot 0511) w la they are controlling the jac sinkers during the advance of the dividers, but at Having described a knitting machine embodying the present invention it is pointed out that the principles thereof may be vari ously embodied and that the claims are not intended to be limited to details of structure or arrangement except to the extent set forth therein.

What is claimed is:

1. In a knitting machine of the type having the following well known elements, the series of bearded needles on which the succescessively to force the thread into-periodic or alternate spaces between needles to form a first set of 100 s of excess de th and to hold them yielding y, the series 0 dividers o rable unitedly, following the operation 0 the sinkers, to force the thread into the remainder of the spaces between needles thereby to form the remaining loops and draw back the first set of loops, the series of spring holding devices adapted to ress the-sinkers toward loop holdlng position, including long-shank springs, one for each sinker, arranged to apply resilient resisting pressure upon the sinkers; the combination, with such elements, of a longitudinal support or block holding the butt ends of all the springs, and a supplemental member or strip arranged to contact and press equally upon the midportions of.

the shanks of all the springs,-durmg the operation of the dividers, to control or ensure uniformity ofthe yielding resistance to the series of jacks cooperating with the sinkers to move and hold them in loop holding position, the series of long-shank jack springs, one for each jack, arranged to apply resilient pressure upon the jacks, and thereby upon the sinkers, to permit their retraction during .the operation of the dividers, a support or bar holding the butt ends of all the jack springs, and a longitudinal contact member or abutment. arranged to contact upon the shanks of all the springs, during the action of the dividers, to modify and render uniform the yielding resistance of the sinkers to the drawing back of the first set-of loops.

4- namaaa 3. A knitting machine as in claim 1 and wherein the contact member is arranged in constant contact with all the springs along a lon itudinal'line, and is formed with a longitu mal contact edge alon which each spring may independently sli e laterally of its own length. y

' 4. A knitting machine as in claim 2 and wherein the contact member consists of a longitudinal strip itself possessing resilience re- 7 mforcing'thatof the respective sprinfs'along a line between the held and free en s of the s rm I 5. f: a knitting machine of the kindre- 1 ferred to, in combination with the series of sinker jacks, the series of long-shank iack springs, one for each jack, arranged to apply resilient pressure upon the jacks, and thereby upon the sinkers, and a supporting bar 50 holding the butt ends of allthe ack springs; a longitudinal contact member, arranged to contact upon the shanks of all the sprin at a point between their held and free en s, y to modify and render uniform the yielding g5 resistance of the jacks and sinkers.

6. A machine as in claim 5 and wherein the contact member is a strip in constant contact u n the springs and constructed to allow sli ing play of the springs along the so contact line.

A machine as in claim 5 and wherein the contact member is" astrip in constant contact u on the sprin s and constructed to allow sli ing' play of t e springs along the 35 contact line, and said strip being mounted and held in the same supporting bar as the sprin 8. n a knittin machine of the kind referred to, in com ination with the series of sinker jacks, the series of long-shank jack springs, one for each jack, arranged to apply resilient pressure upon the jacks, and thereby upon the sinkers, and a sup orting bar clamping the butt ends of all t e jack springs; a

4 lon 'td'dinal contact member, arranged to app y a constant reenforcing contact equally upon the shanks of all the s rin at a con tact line" between their hel an free ends,

a and at their sides opposite to their pressure '5 upon the sinkers.

9. A machine as in claim 8 and wherein the springs are free to flex bothbetween the k contact line and their free ends, and the contact line and their clamped ends. as, 10. A machine as in claini- 8 and wherein the springs are free to flex both between the contact line and their free ends, and t e con tact line and their clamped ends, and e contact member is itself a stiiily resilient longiso tudinal strip.

In testimony whereof, this specification has been duly signed by: J

ALFRED HQFMANN. 

